1. Field of the Invention
The present invention relates generally to apparatus for testing properties of semiconductor chips, such as light emitting diode (hereinafter referred to as “LED”) chips, and more particularly to a probing apparatus equipped with a heating device for heating chips under test.
2. Description of the Related Art
In a task of testing properties of semiconductor chips, such as LED chips, the step of testing the thermal resistance to high temperature of the chips is usually included. For running the thermal resistance test, the conventional probing apparatus is usually equipped with a heating device for heating chips under test. Such conventional probing apparatus is usually composed of a rotating device having a plurality of platforms for supporting devices under test (hereinafter referred to as “DUTs”), a heating device mounted in the rotating device and provided with a plurality of electrical heaters attached to the platforms, and a probe device. The heaters are used to heat the platforms respectively, such that the DUTs supported on the platforms can be indirectly heated by the heaters to a desired temperature, e.g. 80 to 90 degrees centigrade, qualified for running the thermal resistance test. In addition, the rotating device is used to sequentially move the platforms to a test position, which corresponds in location to the probe device, by a revolving motion, such that the DUTs having been heated to the desired temperature can be tested by the probe device one after another.
In order to achieve the function that the heaters of the heating device are fixed relative to the platforms respectively and will revolve along with the rotating device, the heating device in the conventional design needs to be equipped with a slip ring for electricity transmission to the heaters, and the heating device usually has a complicated arrangement of electric wires thereof. As a result, the electric wires of the heating device tend to break or bad electrical contacts may happen after the conventional probing apparatus undergoes a long period of working time. In other words, the conventional probing apparatus is still defective and need further improvement.